Grokking the System Design Interview

System Design Interviews: A step by step guide
	Step 1: Requirements clarifications
	Step 2: System interface definition
	Step 3: Back-of-the-envelope estimation
	Step 4: Defining data model
	Step 5: High-level design
	Step 6: Detailed design
	Step 7: Identifying and resolving bottlenecks
	Summary
Designing a URL Shortening service like TinyURL
	1. Why do we need URL shortening?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. System APIs
	5. Database Design
		Database Schema:
	6. Basic System Design and Algorithm
	a. Encoding actual URL
	b. Generating keys offline
	7. Data Partitioning and Replication
	8. Cache
	9. Load Balancer (LB)
	10. Purging or DB cleanup
	11. Telemetry
	12. Security and Permissions
Designing Pastebin
	1. What is Pastebin?
	2. Requirements and Goals of the System
	3. Some Design Considerations
	4. Capacity Estimation and Constraints
	5. System APIs
	6. Database Design
		Database Schema:
	7. High Level Design
	8. Component Design
	a. Application layer
	b. Datastore layer
	9. Purging or DB Cleanup
	10. Data Partitioning and Replication
	11. Cache and Load Balancer
	12. Security and Permissions
Designing Instagram
	1. What is Instagram?
	2. Requirements and Goals of the System
	3. Some Design Considerations
	4. Capacity Estimation and Constraints
	5. High Level System Design
	6. Database Schema
	7. Data Size Estimation
	8. Component Design
	9. Reliability and Redundancy
	10. Data Sharding
	11. Ranking and News Feed Generation
	12. News Feed Creation with Sharded Data
	13. Cache and Load balancing
Designing Dropbox
	1. Why Cloud Storage?
	2. Requirements and Goals of the System
	3. Some Design Considerations
	4. Capacity Estimation and Constraints
	5. High Level Design
	6. Component Design
	a. Client
	b. Metadata Database
	c. Synchronization Service
	d. Message Queuing Service
	e. Cloud/Block Storage
	7. File Processing Workflow
	8. Data Deduplication
	9. Metadata Partitioning
	10. Caching
	11. Load Balancer (LB)
	12. Security, Permissions and File Sharing
Designing Facebook Messenger
	1. What is Facebook Messenger?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. High Level Design
	5. Detailed Component Design
	a. Messages Handling
	b. Storing and retrieving the messages from the database
	c. Managing user’s status
	6. Data partitioning
	7. Cache
	8. Load balancing
	9. Fault tolerance and Replication
	10. Extended Requirements
	a. Group chat
	b. Push notifications
Designing Twitter
	1. What is Twitter?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. System APIs
	5. High Level System Design
	6. Database Schema
	7. Data Sharding
	8. Cache
	9. Timeline Generation
	10. Replication and Fault Tolerance
	11. Load Balancing
	12. Monitoring
	13. Extended Requirements
Designing Youtube or Netflix
	1. Why Youtube?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. System APIs
	5. High Level Design
	6. Database Schema
	7. Detailed Component Design
	8. Metadata Sharding
	9. Video Deduplication
	10. Load Balancing
	11. Cache
	12. Content Delivery Network (CDN)
	13. Fault Tolerance
Designing Typeahead Suggestion
	1. What is Typeahead Suggestion?
	2. Requirements and Goals of the System
	3. Basic System Design and Algorithm
	4. Permanent Storage of the Trie
	5. Scale Estimation
	6. Data Partition
	7. Cache
	8. Replication and Load Balancer
	9. Fault Tolerance
	10. Typeahead Client
	11. Personalization
Designing an API Rate Limiter
	1. What is a Rate Limiter?
	2. Why do we need API rate limiting?
	3. Requirements and Goals of the System
	4. How to do Rate Limiting?
	5. What are different types of throttling?
	6. What are different types of algorithms used for Rate Limiting?
	7. High level design for Rate Limiter
	8. Basic System Design and Algorithm
	9. Sliding Window algorithm
	10. Sliding Window with Counters
	11. Data Sharding and Caching
	12. Should we rate limit by IP or by user?
Designing Twitter Search
	1. What is Twitter Search?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. System APIs
	5. High Level Design
	6. Detailed Component Design
	7. Fault Tolerance
	8. Cache
	9. Load Balancing
	10. Ranking
Designing a Web Crawler
	1. What is a Web Crawler?
	2. Requirements and Goals of the System
	3. Some Design Considerations
	4. Capacity Estimation and Constraints
	5. High Level design
	How to crawl?
	Difficulties in implementing efficient web crawler
	6. Detailed Component Design
	7. Fault tolerance
	8. Data Partitioning
	9. Crawler Traps
Designing Facebook’s Newsfeed
	1. What is Facebook’s newsfeed?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. System APIs
	5. Database Design
	6. High Level System Design
	7. Detailed Component Design
	8. Feed Ranking
	9. Data Partitioning
Designing Yelp or Nearby Friends
	1. Why Yelp or Proximity Server?
	2. Requirements and Goals of the System
	3. Scale Estimation
	4. Database Schema
	5. System APIs
	6. Basic System Design and Algorithm
	a. SQL solution
	b. Grids
	c. Dynamic size grids
	7. Data Partitioning
	8. Replication and Fault Tolerance
	9. Cache
	10. Load Balancing (LB)
	11. Ranking
Designing Uber backend
	1. What is Uber?
	2. Requirements and Goals of the System
	3. Capacity Estimation and Constraints
	4. Basic System Design and Algorithm
	5. Fault Tolerance and Replication
	6. Ranking
	7. Advanced Issues
Design Ticketmaster (*New*)
	1. What is an online movie ticket booking system?
	2. Requirements and Goals of the System
	3. Some Design Considerations
	4. Capacity Estimation
	5. System APIs
	6. Database Design
	7. High Level Design
	8. Detailed Component Design
	9. Concurrency
	10. Fault Tolerance
	11. Data Partitioning
Additional Resources
System Design Basics
Key Characteristics of Distributed Systems
	Scalability
	Reliability
	Availability
	Efficiency
	Serviceability or Manageability
Load Balancing
	Benefits of Load Balancing
	Load Balancing Algorithms
	Redundant Load Balancers
Caching
	Application server cache
	Content Distribution Network (CDN)
	Cache Invalidation
	Cache eviction policies
Sharding or Data Partitioning
	1. Partitioning Methods
	2. Partitioning Criteria
	3. Common Problems of Sharding
Indexes
	Example: A library catalog
	How do Indexes decrease write performance?
Proxies
	Proxy Server Types
		Open Proxy
		Reverse Proxy
Redundancy and Replication
SQL vs. NoSQL
	SQL
	NoSQL
	High level differences between SQL and NoSQL
	SQL VS. NoSQL - Which one to use?
	Reasons to use SQL database
	Reasons to use NoSQL database
CAP Theorem
Consistent Hashing
	What is Consistent Hashing?
	How does it work?
Long-Polling vs WebSockets vs Server-Sent Events
	Ajax Polling
	HTTP Long-Polling
	WebSockets
	Server-Sent Events (SSEs)